Which cryptographic technique ensures that a message has not been altered during transmission?
- Encryption
- Hashing
- Digital Signature
- Both B and C
Answer: Both B and C
Hashing (e.g., SHA-256) generates fixed-size digest to detect changes; any modification alters the hash. Digital Signatures combine hashing with asymmetric encryption to also verify sender identity and provide non-repudiation. Both ensure integrity; signatures add authentication and legal validity.